Seongjwadeuri Nae Jeja

300 years ago, the invincible warrior Hyeon-Oh Kim brought down the Tower of the End, preventing the world’s demise. Though he should have died the moment the Tower of the End collapsed, Hyeon-Oh is reborn 300 years later in the body of a 17-year-old boy named Ju-Hyeok Kim. Meanwhile, he discovers the existence of the Constellations, who were once his disciples 300 years ago but were born during the time when he did not exist in this world. Will he be able to find them again and train them?
(Source: WEBTOON, edited)